A marketer has started using Datorama Reports to enhance their email performance and engagement monitoring, which feature should improve Datorama Dashboard usability?

A marketer is configuring Path Optimizer in Journey Builder to test three different email subject lines. They want to configure a holdback audience to receive the winning path, but the option is unavailable.
Why would the marketer be unable to configure a holdback audience?

Northern Trail Outfitters third-party point-of-sale software order information in batches of large files. the timing varies throughout the day.
Which feature should be used to accommodate this setup?

When creating a custom email with the HTML Paste Editor, which feature can be inserted into the HTML code by using the Insert Tools? (Choose 2)

Northern Trail Outfitters (NTO) needs to create a sendable data extension that will contain its customers' information. NTO's customers are identified by a unique alphanumeric Customer ID, and Email Address is a required field.
How should the data extension be configured?